Lucy Aquino, Paraguay

Before Lucy Aquino's efforts led to the passage of the Zero Deforestation law in December 2004, between 217,000 and 420,000 acres of Paraguay's tropical forest were lost each year to logging and agricultural clearing. The country's rapid rate of deforestation, by 2002 the second highest in the world, eventually wiped out 88 percent of its forests and drove indigenous people off their land. Many indigenous women moved to cities, where they earned livings through begging and prostitution, while the men worked on the plantations that replaced the forests.

Aquino, an Asuncion-born biologist working with the World Wildlife Fund, had two goals. Her negotiations with government officials and forest communities resulted in a 9-year moratorium on deforestation in the Paraguayan part of the Atlantic Forest, home to thousands of animal and plant species. Since then, deforestation in Paraguay has fallen by 85 percent, and Brazil and Argentina are developing a plan to conserve their own sections of the Atlantic Forest. Aquino has also worked to return the indigenous people to their land and make possible sustainable use of the forest. The tree nurseries that she established employ indigenous women, who raise saplings for medicinal purposes and to repopulate deforested areas.

Pati Ruíz Corzo, Mexico

At one point the Sierra Gorda region in Querétaro, Mexico, a Rhode Island-sized area home to 432 animal species and six different ecosystems, faced a slew of environmental problems that included deforestation and soil erosion. Widespread use of wood for cooking and heating took a toll on the forests, while forest clearing led to lowered groundwater levels. The battered land found its advocate in Pati Ruíz Corzo, a former music teacher who left behind an affluent life in urban Querétaro to migrate to the mountains of Sierra Gorda, where her husband was born, seeking a simpler and more environmentally sustainable existence for her family.

Ruíz Corzo saw the need to provide economic incentives in addition to educating the community on the importance of conservation. "To preserve the environment, I have to go hand-in-hand with the locals," she explains. To inform them, she trekked throughout Sierra Gorda, playing an accordion and singing songs about the environment. And to motivate the nearly 100,000 area residents to participate in conservation, the Grupo Ecologico Sierra Gorda, which Ruíz Corzo founded with her husband, provided them with sustainable income and offered monetary incentives to landowners not to cut down trees. The success of her grassroots movement prompted the government to designate the region a federally protected area, the first in Mexico. In 2001, UNESCO named Sierra Gorda a World Biosphere Reserve.

The land has yet to recover fully, but Ruíz Corzo's work has already inspired other plans of conservation. Recently, the adjacent state of Guanajuato preserved its own part of Sierra Gorda as a biosphere reserve.

Ikal Angelei, Kenya

While controversy over the proposed Belo Monte dam brewed in the Amazon, roughly 300,000 people living near Kenya's Lake Turkana saw their livelihood threatened by construction of the Gibe III dam on Ethiopia's Omo River, which supplies the lake with 90 percent of its inflow. Ikal Angelei, an energetic young activist and member of one of the many indigenous communities dependent on the desert lake for fishing and farming, learned about the potential effects of the dam while working at the Turkana Basin Institute. The dam would cut the inflow of Lake Turkana in half for years and potentially devastate its ecological balance and nearby wildlife, yet residents were not consulted during the dam's planning process.

Angelei's first step was mobilizing the local tribes. In 2008, she founded Friends of Lake Turkana, a community-based group that holds demonstrations against what is planned to be Africa's largest dam. As a result of Angelei's tireless lobbying, the World Bank, the African Development Bank, and the European Investment Bank will not provide financial assistance to the project in spite of earlier interest, and construction has stalled due to lack of funding. In face of the uncompromising stance of Ethiopian authorities and Chinese investors, Angelei continues to rally support, recently from the United Nations' World Heritage Committee, which declared Lake Turkana a World Heritage Site in 1997.

The Judges

The following individuals helped select this year's winner and runners-up

Frances Beinecke, president, Natural Resources Defense Council

John Paul DeJoria, co-founder and chairman, John Paul Mitchell Systems